Door closing and checking mechanism.



P. A. SMITHURST.

DOOR CLOSING AND CHECKING MECHANISM.

APPLICATION FILED DEC. 23, 1912.

Patented Oct. 28,1913.

Inn" 267.

COLUMBIA PLANOORAPH CO.,WASHINGTON. n. c.

PERCY ALLIOTT SMITHURST, OF LONDON, ENGLAND.

DOOR CLOSING AND CHECKING MECHANISM.

Specification of Letters Patent.

Patented Oct. 28, 1913.

Application filed December 23, 1912. Serial No. 738,355.

To all whom 2'15 may concern Be it known that I, PERCY ALLrorr Smrnonsr, a subject of the King of Great Britain, residing at London, England, have v of the barrel on the piston, the saidbarreland piston forming the air-check device,

the parts coacting so that the energized spring effects the closing of the door which closing is checked or retarded as the doorf approaches its closed position in order to prevent slamming. 7

By the improvements hereinafter described it will be observed that the compression of the spring is effected by a lever or bar interposed between a fixed abutment and a sliding plunger within the barrel,

whereby an increased leverage is obtained in the closing effect when the spring becomes less powerful toward the end of the closing operation, and the air-check plunger isoperated separately by independent means,

In order that my said invention may be fully understood, I will proceed to describe the same with the aid of the accompanying sheet of drawings, in which Figure 1 is an elevation of a door-closing and checking mechanism constructed 1n accordance with myinvention; Fig. 2 a plan View of same; Fig. 3 is a plan view-simi- 7 lar to that shown in Fig. 2 but partly in horizontal section; and Fig. 4: a similar plan v1ew showing a modlficatlon 1n the construction of the air-check plunger and the application of an automatically actuated valve for destroying the retarding efiect of the air-check as the door approaches the closed position.

According to my invention I attach a bracket a .to the door frame I), and to this bracket a I pivot, at 0, a tubular closing lever d, which is connected to the door 6 by means of a slide-guide f in which the end of the said tubular lever cl is adapted to slide to a limited extent. On the bracket a is a pivot g on which is mounted. one end of a short bar it, the other end of which enters the adjacent open rear end of the tubular lever d and engages with a plug 2' free to the fixed abutment 7c.

attachment of the tubular'lever d and the slide in the said lever. Against the inned end of this plug '5 presses one end of an energized helical spring j compressed between the said plug 2' and a fixed abutment 70 within the tubular lever 03. The bar it is preferably held in position by the pressure of the energized spring 7', that is to say its outer end may be so shaped, as shown in Fig. 3, as to bear against its pivot g on the bracket a, and its inner end may be so shaped as to rock in a curved recess in the outer end of the plug 2', so that the said bar it is free to fall or be lifted away on the removal from it of the pressure of the energized spring 7'. At a suitable point on the bracket a, as at m for example, is also pivotally mounted a bar 9?. which extends exteriorly of the tubular lever (Z to the farther end thereof, where it is pivotally connected to the outer end of a plunger 3) which slides more or less airtight within that portion of the tubular lever (Z which is on the opposite side of the fixed abutment 7': to that against which the spring 7' bears as before explained. This plunger 79 is preferably fitted with a cup-leather g, and acts as. an air-check, a 7

small hole governed by a regulating screw, 9, or any suitable arrangement of adjustable escape valve, being provided to allow of the gradual escape ofair from the space between the innerend of the The points of pivotal bar h respectively to the bracket or are preferably so disposedv that when the door is in the open position those two points are both in the line of force of the energized spring j, so that the spring has then no closing efiec't upon the door, and the latter can be left in the open position when desired. p g

It will now be understood that the act of opening the door 6 will cause the tubular lever (Z to turn on its pivot c on the fixed bracket 0, and the energized or partly compressed spring 7 to be further compressed, as the bar it forces the plug 2' farther into the tubular lever (Z, and the external bar 'n will also cause the air-check plunger 79 to make a stroke outward. Upon the door being re-' leased the compressed spring 7' acting upon the abutment g on the bracket. a through the plug z and bar it will, by acting upon the abutment in, force the tubular lever d, and with it the door, into the closed position, as shown in the drawings, but the latter part of plunger 79 1 and the closing movement will be checked or relow the free entrance of air between the end of the air-check plunger 79 and the central abutment 70 in the pivoted tubular lever (Z during the outward stroke of such plunger, instead of attaching the cup-leather q directly to the end of the plunger as described and shown in Fig. 3, I attach it to a loose end 8 which is carried by a pin 25 eX- tending centrally from the end of the 1 plunger 79. A. washer a is interposed between the end of the plunger 79 and the loose end 8, which latter is free to move on thei central pin t for a short distance longitudinally of the axis of the plunger 79. Air pasj sages o are formed between the forward and 1 backward ends of the loose end 8, which passages 12 are closed by the beforelnentioned washer it whenever the loose end 8 is pressed toward the plunger, that is to say at the forward stroke thereof; but when the passages a are not so closed, that is to say at the backward stroke of the plunger, the air from the outer atmosphere is free to pass into the space between the loose end 5 and plunger p by suitable passages to formed in the end walls of the hollow plunger 79, and thence into the space between the cup-leather Q" and the beforementioned central abutment by the said passages 12 in the loose end 8. It will be understood that when the plunger ;0 is withdrawn from the tubular lever (Z by the opening of the door a, the first pull on the plunger 79 will cause it to move away from the loose end 8 and uncover the air passages o. Air will then freely pass from the outer atmosphere through the passages 10 in the plunger 79, into the space between the loose end 5 and the end of the plunger 79, and through the uncovered passages o in the loose end 8 into the gradually increasing space between the cup leather g and the central abutment 7c in the tubular lever 6!. But on the reverse movement of the plunger 79 while the door is closing, the first inward movement will press the plunger p, washer a, and loose end .9 all close together thereby closing the air passages t in the loose end .9 and insure that the air contained in the tubular lever (Z shall pass through the opening governed by the ordinary regulating screw 9, or otherwise.

In some cases it is desirable that the retarding effect of the air-check should more or less suddenly cease as the door appreaches the closed position, (as for example when the latch of the door is sluggish in action), and the full effect of the spring be exerted for the final closing of the door 6. For this purpose I provide an outwardly closing spring valve 00 suitably mounted in the central. abutment k of the tubular lever d with its stem 1 projecting from the eX- terior of the lever (Z in such a position that it comes within the path of a cam 2 mounted upon the external bar a which connects the outer end of the air-check plunger 79 to the bracket a fixed to the door frame 6, by which inclined cam surface a the valve 50 is caused to open against the resistance of its spring 0, and the compressed air contained between the acting end of the plunger 79 and the central abutment 7c of the tubular lever 01 is thereby allowed to escape freely, and the door-closing spring j, being no longer checked, closes the door 6 suddenly. The cam z is preferably mounted upon the bar we in such a manner that its position thereupon may be adjustably regulated according to requirements.

Claims:

1. A door-closing and checking 1nechanism which consists of a tubular lever pivoted to a fixed bracket, an energized spring contained within said tubular lever, means for compressing said spring as the door is opened, an air-check plunger device in said tubular lever, and means for actuating said plunger separate from and independent of those for compressing said spring, substantially as described.

2. A door closing and checking mechanism which consists of a tubular lever pivoted to a fixed bracket, an energized spring contained within said lever, means for compressing said spring which consists of a fixed abutment on said bracket, a plug within said tubular lever and a bar engaging said abutment and extending within said tubular lever and engaging said plug, an air check plunger device in said tubular lever and means for actuating said plunger separate from and independent of those for compressing said spring, substantially as clescribed.

3. A door closing and checking mechanism which consists of a tubular lever pivoted to a bracket, an energized spring contained within said tubular lever, a fixed abutment on said bracket, a plug within said tubular lever and operatively engaging said spring, a bar engaging said abutment and said plug, an air check plunger contained within said tubular lever and furnished with a loose end, said loose end having air passages extending therethrough, a washer interposed between said loose end and the end of said plunger, the inner end of said plunger having air passages extending therethrough and means for operating said air check plunger, substantially as described.

4:. A door closing and checking mechanism which consists of a tubular lever pivoted to a bracket, an energized spring con: tained within said tubular lever, a fixed abutment on said bracket, a plug within said tubular lever and operatively engaging said spring, a bar engaging said abutment and said plug, an air check plunger contained within said tubular lever, a bar connecting said air check plunger with said bracket, an abutment within said lever between said spring and the inner-end of said plunger and provided with an opening I communicating with the atmosphere and with the space between said abutment and said plunger, a valve controlling said opening, means normally tending to hold said valve closed and means for moving said valve into its open position when the door approaches its closed position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

PERCY ALLIOTT SMITHURST.

Witnesses:

STEPHEN EDWARD GUNYON, ALEXANDER EDWARD BECK.

0opies,o this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

